Model 2651A High Power System SourceMeter® Instrument Reference Manual
Section 2: General operation
2651A-901-01 Rev. A / March 2011
2-55
The safety shield can be metallic or nonmetallic, and must completely surround the DUT test circuit. A
metal safety shield must be connected to a known safety earth ground and chassis ground. See
(on page 2-57) later in this section for important safety information on the use of a metal or
nonmetallic enclosure.
Model 2651A safety shield
The maximum output voltage for a Model 2651A channel is 40 V, which is considered a
nonhazardous level. However, using two Model 2651A voltage sources in a series configuration or
(on page 2-58) can cause test circuit voltage to exceed 42 V. In the following figure,
the source-measure units (SMUs) of two Model 2651A instruments can be connected in series to
apply 80 V to a device under test (DUT) (see
(on page 6-53) for information
on using multiple Model 2651A).
Use #18 AWG wire or larger for connections to safety earth ground and chassis.
Figure 21: Safety shield for hazardous voltage using two Model 2651A instruments
G
G G G
S
LO
SENSE/GUARD
S
HI
LO
HI
OUTPUT
40V, 50A MAX.
Model 2651A (subordinate)
G
G G G
S
LO
SENSE/GUARD
S
HI
LO
HI
OUTPUT
40V, 50A MAX.
DUT
LO
HI
HI
LO
HI
LO
Chassis
Chassis
ground
Safety
earth
ground
Safety
earth
ground
Chassis
earth
ground
LO
HI
HI
LO
DUT
HI
LO
SMU
(subordinate)
SMU
(master)
40 V
40 V
80 V
Metal safety shield
Equivalent
Model 2651A (master)